misspedantic not wanting to lay a guilt trip as lots of mums recommend doing what you've just done, but personally I tend to give the benefit of the doubt about food because my dc's appetites are very much affected by emotions and my dd (who is 4) cannot eat properly when she is tired or keyed up. My son has ASD so is a different case but under certain circumstances he will be hungry to the point of hypoglycemia and still not eat.
As I have had it explained to me on a course on wellbeing for adults, appetite is a funny thing, the brain can override hunger messages when there are strong emotions like stress, anger or excitement and of course if we don't eat for a long time and our blood sugar level drops then we can actually feel sick and not like eating any more.
Some people - like my dad - have regular appetites and can always manage to eat three square meals a day and nothing in between; others like my mum are grazers and pickers and have appetites which are capricious - both had the same sort of rules around mealtimes growing up! As an adult I have been taught it is not a healthy habit to eat when you are not hungry and I have been impressed with the way my children will not do so - even leaving half a slice of cake or biscuit when their appetite is satisfied! I don't want to change this so I have opted to respect their own judgement about food within reason.
So can you find a rhythm that suits your daughters' natural appetite without breaking the bank or wearing you out? When my dd is not eating well I give her things like bits of cheese and raw veg to nibble on through the afternoon, then something starchy and light like toast and hot milk before bedtime. It all gets eaten, doesn't cost much, and has the same nutritional value as a plate of pasta at dinnertime. I find if my dd is really hungry plain bread will usually be accepted without being exciting enough to hold out for.
Also, not eating cooked food can be a sign that my dc's are fighting off a cold, because at those times they often just want toast or cereal, bananas or something bland to pick at. My daughter also gets hyper at that time before she crashes so it is all most confusing.
Don't feel bad though - you are just trying to do your best for your daughter - she will be fine! but hopefully you will be able to find a solution that works for both of you without leaving you feeling like a short-order chef in a roadside diner!